Flood as a disaster
July 26, Mumbai was one of the heaviest rainfall day, Mumbaites had seen over the past country. In the morning citizens had inclination that by dusk the city would be swamped. By sunset 435 residents had either drowned in their houses or vehicles as rain water started rising with alarming rapidity. By night the citizens had no transport, no electricity and no place to go. It poured 944.2 mm over 24 hours, the highest in 100 years. By 5 p.m many were dead and the low lying areas of kurala, Ghatkoper, Andheri, Dadar, Juhu anf Kalina were flooded.

Monsoon is known for its uncertainties, it is clear by the following reasons:
(i) The alternation of wet and dry spells vary in intensity, frequency, and distribution.
(ii) While it is responsible for heavy floods in one part, it is responsible for droughts in other parts.
(iii) Generally, it is irregular in its arrival and its retreat. Most of the time its come late from the due date of its arrival.

(i) A low pressure trugh is shifted to the Bay of Bengal by October with the decrease in temperature overnorthern India. This leads to the formation of cyclonic depressions in the Bay of Bengal.
(ii) Cyclonic winds strike the eastern coasts of Andhra Pradesh and Tamil-nadu causing destructive and heavy rain fall. These cyclonic depression are very destructive and havoc.They do a lot of damage to life and property in the delta of krishna, Kaveri and avari.

Tamil Nadu coast receives winter rainfal of the following reasons:
(a) Tamil Nadu coast lies on the eastern coast of the peninsula. During summer, Arabian Sea branch of southwest monsoon ascends on the Western Ghats and causes ,aximum rainfall on its western side. On the other hand, the Tamil Nadu coast remains dry due to its location off the way of south-west monsson as moving towards east they go on shedding their moisture.
(b) During winter, the north-east dry monsson winds blow over the Bay of Bengal. As they pass over the Bay of Bengal they pick up moisture and bring rain to the Tamil Nadu coast as now they are under the effect of on-share winds, full of moisture.

(i) When the tropical Eastern South Pacific Ocean experiences high pressure, the tropical Eastern Indian Ocean experiences low pressure. In this condition, the monsoon rainfall will be average.
(ii) In some years, it is reverse when the pressure difference is negative - means below average and late monsoon.
(iii) The change in pressure conditions is connected to the EL Nino.

(a) Location
1. India is located between 8° N to 37° N latitudes.
2. Tropic of Cancer divides the country into two - equal halves - North sub-tropical zone and South tropical zone.
3. India is surrounded by three water bodies in the south and girdled by a high continuous mountain chain in the North. This compact physical setting gives unique and common climatic framework.
4.The Indian Ocean, Bay of Bengal and Arabian sea have moderating effects on India's climatic condition.
(b) Relief
5. High mountains in the North act as barriers for cold and hot winds. It provides the whole of North India a tropical climate.
6. They may also cause precipitation as they are high enough and lie in the path of rain-bearing winds. For example, the leeward side of Western Ghats remains relatively dry in monsoon season.
7.The Himalayas also force the South-West monsoons to shed all their moisture in the subcontinent. Thus, it can be concluded that location and relief are important factors in determining the climate of India.

Houses in Rajasthan have thick walls and flat roofs.
Thick Walls:
During summer extreme heat is experienced during days.
(i) Thick walls do not allow heat to enter inside the houses.
(ii) They absorb heat and the inside is cool.

Annual range ot temperature = of the hottest month and that of the coldest month.
Annual range of temperature of Jodhpur:
= 33.9 -14.9 =19.0 = 19^oC.

(i) By early, the low pressure condition over the northern plains intensifies.
(ii) It attracts the-trade winds of the southern hemisphere (originate over the souther hemisphere)
(iii) They cross the equator blow in a south westerly direction entering the Indian Peninsula as south-west monsoon.

At Mawsynram, 1080cm